We assessed the acute effect of beetroot extract intake on cardiovascular and autonomic recovery subsequent to strength exercise.This is a crossover, randomized, double-blind and placebo-controlled trial. We assessed 16 subjects but only 12 healthy male adults completed the two protocols in two randomized days: Beetroot extract (600 mg in capsule) and placebo (600 mg starch in capsule). Beetroot extract or placebo was ingested, the subjects endured 120 minutes seated at rest, followed by a 75% 1RM strength exercise and then remained seated for 60 minutes at rest. Cardiorespiratory parameters, heart rate (HR) variability (HRV) (SDNN, rMSSD, pNN50, SD1, SD2 HF [ms]) were estimated before, during exercise and during recovery from exercise.ingestion of beetroot extract before exercise: accelerates the recovery of SBP following physical effort; improves HR recovery to baseline resting levels (beetroot protocol: change in∼62% vs. placebo protocol: change in ∼80%), and intensifies the return of vagal HR control during recovery after exercise.Beetroot extract acutely improved cardiovascular and autonomic recovery after exercise.

Dietary nitrate (NO3-) is converted to nitrite (NO2-) and can be further reduced to the vasodilator nitric oxide (NO) amid a low Oenvironment. Accordingly, dietary NO3- increases hind limb blood flow in rats during treadmill exercise; however, the evidence of such an effect in humans is unclear. We tested the hypothesis that acute dietary NO3- (via beetroot [BR] juice) increases forearm blood flow (FBF) via local vasodilation during handgrip exercise in young adults (n = 11; 25 ± 2 years). FBF (Doppler ultrasound) and blood pressure (Finapres) were measured at rest and during graded handgrip exercise at 5%, 15%, and 25% maximal voluntary contraction (MVC) lasting 4 min each. At the highest workload (25% MVC), systemic hypoxia (80% SaO) was induced and exercise continued for three additional minutes. Subjects ingested concentrated BR (12.6 mmol nitrate (n = 5) or 16.8 mmol nitrate (n = 6) and repeated the exercise bout either 2 (12.6 mmol) or 3 h (16.8 mmol) postconsumption. Compared to control, BR significantly increased FBF at 15% MVC (184 ± 15 vs. 164 ± 15 mL/min), 25% MVC (323 ± 27 vs. 286 ± 28 mL/min), and25% + hypoxia (373 ± 39 vs. 343 ± 32 mL/min) and this was due to increases in vascular conductance (i.e., vasodilation). The effect of BR on hemodynamics was not different between the two doses of BR ingested. Forearm VOwas also elevated during exercise at 15% and 25% MVC. We conclude that acute increases in circulating NO3- and NO2- via BR increases muscle blood flow during moderate- to high-intensity handgrip exercise via local vasodilation. These findings may have important implications for aging and diseased populations that demonstrate impaired muscle perfusion and exercise intolerance.

PURPOSE:We investigated the effects of an acute 24-h nitrate-rich beetroot juice supplement (BR) on the energy cost, exercise efficiency and blood pressure responses to intermittent walking at different gradients.

METHODS:In a double-blind, cross-over design, eight participants were provided with a total of 350 ml of nitrate-rich (~ 20.5 mmol nitrate) BR or placebo (PLA) across 24 h before completing intermittent walking at 3 km/h on treadmill at gradients of 1, 5, 10, 15 and 20%.

RESULTS:Resting mean arterial pressure (MAP) was ~ 4.1% lower after BR (93 vs. 89 mmHg; P = 0.001), as well as during exercise (102 vs. 99 mmHg; P = 0.011) and recovery (97 vs. 94 mmHg; P = 0.001). Exercising (1227 vs. 1129 ml/min P < 0.001) and end-stage (1404 vs. 1249 ml/min; P = 0.002) oxygen uptake ([Formula: see text]O) was lower in BR compared to PLA, which was accompanied by an average reduction in phase II [Formula: see text]Oamplitude (1067 vs. 940 ml/min; P = 0.025). Similarly, recovery [Formula: see text]O(509 vs. 458 ml/min; P = 0.001) was lower in BR. Whole blood potassium concentration increased from pre-post exercise in PLA (4.1 ± 0.3 vs. 4.5 ± 0.3 mmol/L; P = 0.013) but not BR (4.1 ± 0.31 vs. 4.3 ± 0.2 mmol/L; P = 0.188).

CONCLUSIONS:Energy cost of exercise, recovery of [Formula: see text]O, MAP and blood markers were ameliorated after BR. Previously-reported mechanisms explain these findings, which are more noticeable during less-efficient walking at steep gradients (15-20%). These findings have practical implications for hill-walkers.

We aimed to determine the effects of a betalain-rich concentrate (BRC) of beetroots, containing no sugars or nitrates, on exercise performance and recovery. Twenty-two (9 men and 13 women) triathletes (age, 38± 11 years) completed 2 double-blind, crossover, randomized trials (BRC and placebo) starting 7 days apart. Each trial was preceded by 6 days of supplementation with 100 mg·day(-1) of BRC or placebo. On the 7th day of supplementation, exercise trials commenced 120 min after ingestion of 50 mg BRCor placebo and consisted of 40 min of cycling (75 ± 5% maximal oxygen consumption) followed by a 10-km running time trial (TT). Subjects returned 24 h later to complete a 5-km running TT to assess recovery. Ten-kilometer TT duration (49.5 ± 8.9 vs. 50.8 ± 10.3 min, p = 0.03) was faster with the BRC treatment. Despite running faster, average heart rate and ratings of perceived exertion were not different between treatments. Five-kilometer TT duration (23.2 ± 4.4 vs 23.9 ± 4.7 min, p = 0.003), 24 h after the 10-km TT, was faster in 17 of the 22 subjects with the BRC treatment. Creatine kinase, a muscle damage marker, increased less (40.5 ± 22.5 vs. 49.7 ± 21.5 U·L(-1), p = 0.02) from baseline to after the 10-km TT and subjective fatigue increased less (-0.05 ± 6.1 vs. 3.23 ± 6.1, p = 0.05) from baseline to 24 h after the 10-km TT with BRC. In conclusion, BRC supplementation improved 10-km TT performance in competitive male and female triathletes. Improved 5-km TT performances 24 h after the 10-km TT and the attenuated increase of creatine kinase and fatigue suggest an increase in recovery while taking BRC.

To assess the effect of beetroot juice (BET) on recovery kinetics of physical performance, muscle damage and perceived muscle soreness after simulated soccer match play in soccer players.In a randomized, double-blind, crossover design, thirteen soccer players completed the Loughborough Intermittent Shuttle Test LIST. Players received either BET or placebo (PLA) (2*150) for 7 days (3 days pre-exercise, on the day trial, and 3 days post-exercise). Physical performance (Squat jump: SJ, countermovement jump: CMJ, maximal voluntary contraction: MVC, and 20 meters sprint: SP), blood markers of muscle damage (creatine kinase: CK, Lactate dehydrogenase: LDH), inflammatory parameter (C-reactive protein: CRP) and perceived muscle soreness (DOMS) were assessed at baseline, 0 h, 24 h, 48 h and 72 h following the exercise.Following the LIST, a decrease was observed in CMJ, MVC and SP at 0 h, 24 h, 48 h in both conditions (p < 0.05). However, compared to PLA session, this decrease was significantly attenuated with BET for CMJ at 24 h and at 48 h and for MVC at 0 h, 24 h, 48 h and for SP at 48 h after the LIST (p < 0.05). Likewise, DOMS values were significantly lower with BET compared to PLA condition immediately and at 24 h after exercise.CK, LDH and CRP levels increased at 0 h and at 24 h post exercise in both conditions (p < 0.05), but without any significant difference between the two condition (p > 0.05).The results of the present study suggest that chronic beetroot juice supplementation reduces post exercise perceived muscle soreness and maintain better performance during the recovery period in soccer players.

Chronic heart failure (CHF) results in a greater cost of breathing and necessitates an elevated diaphragm blood flow (BF). Dietary nitrate (NO‾) supplementation lowers the cost of exercise. We hypothesized that dietary NO‾ supplementation would attenuate the CHF-induced greater cost of breathing and thus the heightened diaphragm BF during exercise. CHF rats received either 5days of NO‾-rich beetroot (BR) juice (CHF+BR, n=10) or a placebo (CHF, n=10). Respiratory muscle BFs (radiolabeled microspheres) were measured at rest and during submaximal exercise (20m/min, 5% grade). Infarcted left ventricular area and normalized lung weight were not significantly different between groups. During submaximal exercise, diaphragm BF was markedly lower for CHF+BR than CHF (CHF+BR: 195±28; CHF: 309±71mL/min/100g, p=0.04). The change in diaphragm BF from rest to exercise was less (p=0.047) for CHF+BR than CHF. These findings demonstrate that dietary NO‾ supplementation reduces the elevated diaphragm BF during exercise in CHF rats thus providing additional support for this therapeutic intervention in CHF.

Williams, TD, Martin, MP, Mintz, JA, Rogers, RR, and Ballmann, CG. Effect of acute beetroot juice supplementation on bench press power, velocity, and repetition volume. J Strength Cond Res XX(X): 000-000, 2019-The purpose of this study was to examine the effects of acute beetroot juice (BRJ) supplementation on power, velocity, and repetitions to failure (RTF) during bench press exercise. Resistance-trained male subjects (n = 11) were recruited for this study. Using a double-blinded, counterbalanced, crossover study design, subjects were supplemented with either 70 ml of BRJ or placebo (PL; black currant juice) 2 hours before exercise. During each exercise trial, subjects began by completing 2 sets× 2 repetitions of bench press at 70% 1 repetition maximum (1RM) with maximum explosive intent. Barbell velocity and power were measured using a linear position transducer. Subjects then completed 3 sets × RTF at 70% 1RM separated by 2 minutes of rest between each set. Maximum mean power, velocity, and repetitions were analyzed. Mean velocity (p = 0.011; effect size [ES] = 0.54) and mean power (p = 0.015; ES = 0.51) were significantly higher with BRJ when compared with PL. Total RTF (p = 0.002; ES = 0.46) was higher during the BRJ condition vs. PL. Results indicate that acute BRJ supplementation positively impacts velocity, power, and total repetitions during free-weight bench press exercise.

PURPOSE:This study investigated whether reported improvements in blood flow distribution, and the possible related effects on thermoregulation during exercise following supplementation with beetroot juice (BR), a rich source of dietary nitrate (NO), are mitigated in the heat.

METHODS:12 male endurance-trained cyclists (age 27 ± 6 years, VO68.6 ± 8.1 ml kg min) completed two 60 min submaximal cycling trials at 60% of VOpower output. Trials were performed in hot environmental conditions (33.3 ± 0.4 °C, 48.8 ± 3.0% RH) following 3 days of supplementation with either NO-rich BR (6.5 mmol NOfor 2 days and 13 mmol NOon the final day) or NO-depleted placebo (PLA). Salivary NOand nitrite (NO) were measured before and after the supplementation period. During exercise, cutaneous blood flow, blood pressure (MAP), core temperature (T), mean skin temperature (T), indices of muscle oxygenation and oxygen (O) consumption were measured.

RESULTS:Salivary NOand NOincreased significantly following BR by 680 and 890%, respectively. There were no significant differences observed for cutaneous blood flow, MAP, T, T, muscle oxygenation, or Oconsumption between BR and PLA.

CONCLUSION:This investigation shows that the ergogenic effects and health benefits of BR supplementation, such as augmented cutaneous blood flow, reduced MAP, increased muscle oxygenation, and improved aerobic efficiency may be attenuated when exercise is performed in hot conditions.

Beetroot juice contains high levels of inorganic nitrate (NO) and its intake has proved effective at increasing blood nitric oxide (NO) concentrations. Given the effects of NO in promoting vasodilation and blood flow with beneficial impacts on muscle contraction, several studies have detected an ergogenic effect of beetroot juice supplementation on exercise efforts with high oxidative energy metabolism demands. However, only a scarce yet growing number of investigations have sought to assess the effects of this supplement on performance at high-intensity exercise. Here we review the few studies that have addressed this issue. The databases Dialnet, Elsevier, Medline, Pubmed and Web of Science were searched for articles in English, Portuguese and Spanish published from 2010 to March 31 to 2017 using the keywords: beet or beetroot or nitrate or nitrite and supplement or supplementation or nutrition or"sport nutrition"and exercise or sport or"physical activity"or effort or athlete. Nine articles fulfilling the inclusion criteria were identified. Results indicate that beetroot juice given as a single dose or over a few days may improve performance at intermittent, high-intensity efforts with short rest periods. The improvements observed were attributed to faster phosphocreatine resynthesis which could delay its depletion during repetitive exercise efforts. In addition, beetroot juice supplementation could improve muscle power output via a mechanism involving a faster muscle shortening velocity. The findings of some studies also suggested improved indicators of muscular fatigue, though the mechanism involved in this effect remains unclear.

As a nitric oxide precursor, beetroot juice (BJ) is known to enhance high-intensity exercise performance (80⁻100% VO) yet its impacts on higher intensity sprint exercise (>100% VO) remain to be established. This study sought to examine the effects of BJ supplementation on performance and subsequent fatigue during an all-out sprint exercise. Using a randomized cross-over, double-blind, placebo-controlled design, 15 healthy resistance-trained men (22.4± 1.6 years) ingested 70 mL of either BJ or placebo. Three hours later, participants undertook a 30-s all-out Wingate test. Before and after the sprint exercise and at 30 s and 180 s post-exercise, three countermovement jumps (CMJ) were performed and blood lactate samples were obtained. Compared toplacebo, BJ consumption improved peak (placebo vs. BJ, 848 ± 134 vs. 881 ± 135 W;= 0.049) and mean (641± 91 vs. 666 ± 100 W;= 0.023) power output and also reduced the time taken to reach Win the Wingate test (8.9± 1.4 vs. 7.3 ± 0.9 s;= 0.003). No differences were detected in the fatigue index. In addition, while over time CMJ height and power diminished (ANOVA<0.001) and blood lactate levels increased (ANOVA<0.001), no supplementation effect was observed. Our findings indicate that while BJ supplementation improved performance at the 30-s cycling sprint, this improvement was not accompanied by differences in fatigue during or after this type of exercise.

Beyond the well-known effects on blood pressure (BP) of the dietary approaches to stop hypertension (DASH) and the Mediterranean diets, a large number of studies has investigated the possible BP lowering effect of different dietary supplements and nutraceuticals, the most part of them being antioxidant agents with a high tolerability and safety profile. In particular relatively large body of evidence support the use of potassium, L-arginine, vitamin C, cocoa flavonoids, beetroot juice, coenzyme Q10, controlled-release melatonin, and aged garlic extract. However there is a need for data about the long-term safety of a large part of the above discussed products. Moreover further clinical research is advisable to identify between the available active nutraceuticals those with the best cost-effectiveness and risk-benefit ratio for a large use in general population with low-added cardiovascular risk related to uncomplicated hypertension.

OBJECTIVES:This study sought to determine whether a relatively low single dose or a week-long dosage of dietary inorganic nitrate could improve exercise tolerance in patients with heart failure with preserved ejection fraction (HFpEF).

BACKGROUND:Exercise intolerance is the primary manifestation of HFpEF and is largely due to noncardiac factors that reduce oxygen delivery to active skeletal muscles. A recent study showed improved exercise capacity in patients with HFpEF after a single, acute dose of beetroot juice (BRJ) (12.9 mmol inorganic nitrate) while another recent study showed neutral and negative effects of an organic nitrate.

METHODS:Twenty HFpEF patients (69± 7 years of age ) were enrolled in an initial cross-over design comparing a single, acute dose of BRJ (6.1 mmol nitrate) to a nitrate-depleted placebo BRJ. A second phase, 1 week of daily doses, used an all-treated design in which patients consumed BRJ for an average of 7 days. The primary outcomeof the study was submaximal aerobic endurance, measured as cycling time to exhaustion at 75% of measured maximal power output.

RESULTS:No adverse events were associated with the intervention. Submaximal aerobic endurance improved 24% after 1 week of daily BRJ dosing (p = 0.02) but was not affected by the single, acute dose of the BRJ compared to placebo. Consumption of BRJ significantly reduced resting systolic blood pressure and increased plasma nitrate and nitrite in both of the dosing schemes.

CONCLUSIONS:One week of daily dosing with BRJ (6.1 mmol inorganic nitrate) significantly improves submaximal aerobic endurance and blood pressure in elderly HFpEF patients.

This article provides an overview of the current literature relating to the efficacy of dietary nitrate (NO) ingestion in altering aspects of cardiovascular and metabolic health and exercise capacity in healthy and diseased individuals. The consumption of NO-rich vegetables, such as spinach and beetroot, have been variously shown to promote nitric oxide bioavailability, reduce systemic blood pressure, enhance tissue blood flow, modulate muscle Outilisation and improve exercise tolerance both in normoxia and in hypoxia, as is commonly observed in a number of disease states. NOingestion may, therefore, act as a natural means for augmenting performance and attenuating complications associated with limited Oavailability or transport, hypertension and the metabolic syndrome. Recent studies indicate that dietary NOmight also augment intrinsic skeletal muscle contractility and improve the speed and power of muscle contraction. Moreover, several investigations suggest that NOsupplementation may improve aspects of cognitive performance both at rest and during exercise. Collectively, these observations position NOas more than a putative ergogenic aid and suggest that increasing natural dietary NOintake may act as a prophylactic in countering the predations of senescence and certain cardiovascular-metabolic diseases.

This investigation assessed the effect of dietary nitrate (NO) supplementation, in the form of beetroot juice (BR), on repeat-sprint performance in normoxia and normobaric hypoxia. 12 male team-sport athletes (age 22.3 ± 2.6 y, VO53.1 ± 8.7 mL.kg.min) completed three exercise trials involving a 10 min submaximal warm-up and 4 sets of cycling repeat-sprint efforts (RSE; 9 × 4 s) at sea level (CON), or at 3000 m simulated altitude following acute supplementation (140 mL) with BR (HYP; 13 mmol NO) or NOdepleted BR placebo (HYP). Peak (PPO) and mean (MPO) power output, plus work decrement were recorded during the RSE task, while oxygen consumption (VO) was measured during the warm-up. There were no significant differences observed between HYPand HYPfor PPO or MPO; however, work decrement was reduced in the first RSE set in HYPcompared with HYP. There was a moderate effect for VOto be lower following BR at the end of the 10 min warm-up (ES = 0.50 ± 0.51). Dietary NOmay not improve repeat-sprint performance in hypoxia but may reduce VOduring submaximal exercise. Therefore, BR supplementation may be more effective for performance improvement during predominantly aerobic exercise.

Heart failure with reduced ejection fraction (HFrEF) is a common end point for patients with coronary artery disease and it is characterized by exercise intolerance due, in part, to a reduction in cardiac output. Nitric oxide (NO) plays a vital role in cardiac function and patients with HFrEF have been identified as having reduced vascular NO. This pilot study aimed to investigate if nitrate supplementation could improve cardiac measures during acute, submaximal exercise. Five male participants (61± 3 years) with HFrEF (EF 32 ± 2.2%) completed this pilot study. All participants supplemented with inorganic nitrate (beetroot juice) or a nitrate-depleted placebo for ~13 days prior to testing. Participants completed a three-stage submaximal exercise protocol on a recumbent cycle ergometer withsimultaneous echocardiography for calculation of cardiac output (Q), stroke volume (SV), and total peripheral resistance (TPR). Heart rate and blood pressure were measured at rest and during each stage. Both plasma nitrate (mean = ~1028%,= 0.004) and nitrite (mean = ~109%,= 0.01) increased following supplementation. There were no differences between interventions at rest, but the percent change in SV and Q from rest to stage two and stage three of exercise was higher following nitrate supplementation (all>0.05, ES>0.8). Both interventions showed decreases in TPR during exercise, but the percent reduction TPR in stages two and three was greater following nitrate supplementation (= 0.09, ES = 0.98 and= 0.14, ES = 0.82, respectively). There were clinically relevant increases in cardiac function during exercise following supplementation with nitrate. The findings from this pilot study warrant further investigation in larger clinical trials.

This study investigated the influence of dietary inorganic nitrate (NO) supplementation on pulmonary Ouptake (V˙O) and muscle deoxyhemoglobin/myoglobin (i.e. deoxy [Hb + Mb]) kinetics during submaximal cycling exercise. In a randomized, placebo-controlled, cross-over study, eight healthy and physically active male subjects completed two step cycle tests at a work rate equivalent to 50% of the difference between the gas exchange threshold and peak V˙Oover separate 4-day supplementation periods with NO-rich (BR; providing 8.4 mmol NO∙day) and NO-depleted (placebo; PLA) beetroot juice. Pulmonary V˙Owas measured breath-by-breath and time-resolved near-infrared spectroscopy was utilized to quantify absolute deoxy [Hb + Mb] and total [Hb + Mb] within the,, andThere were no significant differences (>0.05) in the primary deoxy [Hb + Mb] mean response time or amplitude between the PLA and BR trials at each muscle site. BR significantly increased the mean (three-site) end-exercise deoxy [Hb + Mb] (PLA: 91 ± 9 vs. BR: 95 ± 12 mol/L,<0.05), with a tendency to increase the mean (three-site) area under the curve for total [Hb + Mb] responses (PLA: 3650 ± 1188 vs. BR: 4467 ± 1315 mol/L sec,=0.08). The V˙Oslow component reduction after BR supplementation (PLA: 0.27 ± 0.07 vs. BR: 0.23 ± 0.08 L min,=0.07) correlated inversely with the mean increases in deoxy [Hb + Mb] and total [Hb + Mb] across the three muscle regions ( = 0.62 and 0.66,<0.05). Dietary NOsupplementation increased Odiffusive conductance across locomotor muscles in association with improved V˙Odynamics during heavy-intensity cycling transitions.